Osg 2907801 Spiral Flute Tap 8-32 Unc Modified Bottoming

Product Description

The OSG 2907801 is a spiral flute tap designed to cut 8-32 UNC internal threads in a wide range of ferrous materials. Built from vanadium high-speed steel (HSS) with a steam oxide finish, it delivers reliable wear resistance and chip evacuation in through-hole and shallow blind-hole applications. The 45-degree right-hand helix drives chips up and out of the hole, reducing the risk of chip packing. With a modified bottoming chamfer, this tap threads close to the bottom of a blind hole while still tolerating minor misalignment during entry. It is sized for use in hand tapping, drill press, or CNC tapping operations on standard 3B-class-of-fit threaded assemblies.

This tap is suited for production and maintenance threading work in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. The 8-32 UNC thread form is common in instrumentation panels, electrical enclosures, machine housings, and light structural assemblies. Machinists, tool and die makers, and maintenance mechanics will find the modified bottoming chamfer useful where thread engagement must begin close to a blind-hole floor without requiring a true bottoming tap pass first.

Key Features

• 45-degree right-hand spiral flute evacuates chips efficiently in blind-hole applications
• Modified bottoming chamfer allows threading close to hole bottom with reduced tap starts
• Vanadium high-speed steel construction provides elevated heat and wear resistance
• Steam oxide coating reduces friction and provides light corrosion resistance during storage
• H2 thread limit holds tight tolerance for 3B class of fit requirements
• Three flutes balance chip load and tool rigidity in the 8-32 size range

Compatibility

Designed for cutting 8-32 UNC threads with a 3B class of fit in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces.

Installation Notes

A licensed machinist or qualified maintenance mechanic should select a drill bit sized to the correct 8-32 tap drill diameter before use. Ensure the workpiece is securely fixtured and the tap is aligned perpendicular to the drilled hole to prevent tap breakage. Apply a compatible cutting fluid or tapping compound appropriate for the workpiece material, particularly when threading stainless steel or hardened steel. Do not exceed the torque limits of the tap for this size class; back off periodically to break and clear chips when tapping by hand.